Black Ash Critter?

[Jeff]

I've mentioned before that I have a problem with the Black Ash on my property. There seems to be many small trees and they grow straight but where they begin to limb out they almost all have a twist in the stem or what looks like a rotten spot. Many of them lose their tops at that point.  Burlkraft and I fell a few of them last week while clearing a potential building spot and discovered something odd.   They have holes LENGTHWISE through the trunks, presumably by some sort of pest. I'm not talking short holes, I'm talking the length of the stem of the tree.  The holes go through otherwise solid wood. No ant galleries or such, but round, neat, bore holes. Holes you could string lamp cord through. I am guessing the holes go up to where the tops become twisted or are breaking and rotting off.

Any idea what could cause this? They certainly are not emerald ash borers. Totally different crime scene.

[Kevin]

That could be clearwing or redhead ash borer.
Doesn't look like the work of one of those pesky Canadian larch borers. ;D

[Jeff]

I dont think its either.  Clearwing work under the bark, and redhead only on dead or cut wood.

[Kevin]

Clearwing work under the bark

I understand they go deep into the sapwood, large 1/4" holes.

In particular, the nature of the galleries and the shape of the exit holes are distinctly different. Clearwing larvae bore deep into the sapwood, while galleries of EAB are confined to the phloem tissue just under the bark. Clearwing borers expel their frass (a mixture of sawdust and excrement) from the tree, which can accumulate in large quantities in bark crevices, branch crotches and on the ground, providing a good sign of an infestation. Conversely, EAB larvae pack their frass tightly within their galleries as they feed. Upon emerging, clearwing borers leave behind a pupal case, which is sometimes found protruding from the emergence hole. Flatheaded borers such as EAB, on the other hand, do not produce a pupal case.

If the tops were broken due to wind damage they might be a host for the redhead.

Redheaded ash borer infestations can also be distinguished from EAB by the presence of large (three-eighths of an inch wide), oval exit holes. Galleries initially form just under the bark and are packed with frass, as is the case with EAB. However, redheaded ash borer galleries are not nearly as serpentine. As larvae mature, they extend their galleries well into the sapwood, usually following the grain of the wood, while EAB galleries are restricted to the phloem.

In addition, redheaded ash borer is restricted to severely weakened, dying and freshly killed trees

[Ron Scott]

Those are the ones that I was going to suggest. There is also the lilac/ash bore that does similar work.

[Jeff]

The trees in question are not dead so wouldnt that rules out the Redhead?

[Jeff]

The holes are probably about 1/4" but dont appear to be in the sap wood.

[Ron Scott]

Best to cut a sample and send it in to extension service for a more positive ID. There is also a bore worm that affects black ash.

[Jeff]

Ron, I have a sample here.  I would probably want to send that to Chippewa county then?

[Ron Scott]

Jeff,

I'd send sample right to MSU Extension at East Lansing with all the information you have on it for their ease of ID.

http://www.pestid.msu.edu/services/howto.html